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Dinosaur Size Comparison

Which is longer? Which stands taller? Search the atlas selection and compare original dinosaur images with measurement rulers and a human reference.

01 / SIZE & SCALE LAB12 DINOSAURS · 7 HEIGHT RECORDS

ONE WORLD · ONE SHARED SCALE

Stand beside a dinosaur.

Scaled by head-to-tail length
A · Tyrannosaurus rexB · TriceratopsYou · 1.7 m
Site dinosaur reconstructions and a human on a shared scaleTyrannosaurus rex 12 m; Triceratops 7 m; Human height 1.7 m. Rulers use sourced measurements; pose and perspective are illustrative. Only the selected dimension is calibrated.ATLAS RECONSTRUCTIONS / LENGTH COMPARISONYOU ARE HEREA · 12 mB · 7 m

Zoom in and swipe to explore · Calibrated by length; pose and perspective are illustrative. Switch modes to compare sourced heights.

100%
TRY A PAIR
ACHOOSE A DINOSAUR12 m

CHOOSE DINOSAUR A

Who joins the comparison?

12 / 12

12 atlas dinosaurs with sourced lengths; height records are added individually. This is a curated selection, not the full atlas.

Length
12 m
Hip height
3.75 m
Explore this dinosaur ↗
BCHOOSE A DINOSAUR7 m

CHOOSE DINOSAUR B

Who joins the comparison?

12 / 12

12 atlas dinosaurs with sourced lengths; height records are added individually. This is a curated selection, not the full atlas.

Length
7 m
Mounted height
2.5 m
Explore this dinosaur ↗
↟PUT YOURSELF IN THE PICTURE

170cm

50 cm220 cm

Move the slider to see yourself beside these dinosaurs.

1.71×

Tyrannosaurus rex is 1.71 times the length of Triceratops.

Length is not height and cannot directly determine mass.
Build your own scale model1:100

A · 12 cm
B · 7 cm

At 1:100, one real-world metre becomes one centimetre in a model. Model results always use centimetres.

Prints current values. Expand teacher answers to include them.

Classroom investigation · suggested ages 10–14

Predict. Measure. Explain.

Goal: calculate linear ratios, convert model lengths and distinguish length from mass. Use paper and a ruler; write a prediction before checking the display.

  1. How many times as long is Tyrannosaurus rex as Triceratops? Show the calculation.
  2. At 1:100, how long should models A and B be? What happens if the denominator doubles?
  3. Can a length ratio be used as a mass ratio? Are human height and dinosaur length the same anatomical dimension?
Teacher answers & discussion
  1. 12 ÷ 7 ≈ 1.71. The ratio is dimensionless and unchanged by switching metres to feet.
  2. A ≈ 12 cm; B ≈ 7 cm. Doubling the denominator halves both model lengths.
  3. No. Mass depends on three-dimensional shape and density. Cubic scaling applies to geometrically similar models of equal density, not automatically to different dinosaurs. Height and body length are only linear-scale references.
Method, sources & reuse

Measurements updated: 2026-09-22. Rounded museum references or named specimens, not species maxima. Triceratops uses Horridus, Stegosaurus uses Apex, and Allosaurus uses the Museon specimen. Length and height calibrate the artwork separately. Rulers use sourced values; illustrated landmarks and poses are approximate. Conversion decimals do not imply fossil precision.

Tyrannosaurus rex · Museum length source ↗　Triceratops · Museum length source ↗　

Free to project and print this activity for non-commercial teaching with credit and sources retained. Ages and timing are planning suggestions, not classroom-trial results. AI-assisted; independent expert review is not claimed. More teaching materials ↗

Extinct Atlas · OliverHart · 2026-09-22 · https://extinctatlas.com/tools/dinosaur-size-comparison